Friday, January 22, 2010

Uncertainties detailed

The real holes in climate science : Nature News

It would appear that "climategate" (and perhaps now the Himalaya glacier mistake in the IPCC report) has led to some prominent climate scientists sounding humbler. Gavin Schmidt at Real Climate has been sounding more modest lately, and he features prominently in the above article, which I hope Nature keeps available for some time.

It's a very good explanation of those areas of climate science which are still poorly understand and/or subject to very uncertain predictions. In short, they are:

1. regional climate predictions,
2. the effect on precipitation,
3. the role of aerosols, and
4. use of proxies for past climate reconstructions.

The short story is: the atmosphere is really, really complicated, and building accurate models of its behaviour on the scale needed for good regional predictions is very, very hard.

I think this probably goes against the modern intuition, at least of younger people who use computers all the time. I suspect that even the use of sophisticated games software, which deal with thousand of options and combinations and seem to create incredibly detailed "worlds" inside a mere household computer, gives the false impression that modelling a column of air (and extending it globally) could not be so hard.

So it is good now and again to be reminded that big uncertainties remain.

But: the big danger of articles like this is that, as we all know, AGW deniers will use absolutely any mistake (no matter how minor) or admission of lack of knowledge to claim that it is totally rubbish and unreliable.

The Nature article does have short "box" on enduring climate change myths, but it just deals with them briefly.

Of course, what deniers also miss is that there is (as far as I know) no particular reason to assume that the areas in which knowledge are still lacking are all matters which will eventually be resolved in a way relatively harmless for humanity. They could all be matters which end up worse than current predictions.

The other issue that people always forget is ocean acidification, about which I have not posted for a while, but there is plenty of new material out there. I remain strongly of the view that it alone is reason to stop CO2 as soon as possible, as it is extremely difficult to tell where the ecological changes that will bring will take us.

No comments: